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Diffstat (limited to 'drivers/dma/idxd')
-rw-r--r--drivers/dma/idxd/registers.h12
-rw-r--r--drivers/dma/idxd/submit.c14
2 files changed, 14 insertions, 12 deletions
diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h
index 7b54a3939ea1..315c004f58e4 100644
--- a/drivers/dma/idxd/registers.h
+++ b/drivers/dma/idxd/registers.h
@@ -440,12 +440,14 @@ union wqcfg {
/*
* This macro calculates the offset into the GRPCFG register
* idxd - struct idxd *
- * n - wq id
- * ofs - the index of the 32b dword for the config register
+ * n - group id
+ * ofs - the index of the 64b qword for the config register
*
- * The WQCFG register block is divided into groups per each wq. The n index
- * allows us to move to the register group that's for that particular wq.
- * Each register is 32bits. The ofs gives us the number of register to access.
+ * The GRPCFG register block is divided into three sub-registers, which
+ * are GRPWQCFG, GRPENGCFG and GRPFLGCFG. The n index allows us to move
+ * to the register block that contains the three sub-registers.
+ * Each register block is 64bits. And the ofs gives us the offset
+ * within the GRPWQCFG register to access.
*/
#define GRPWQCFG_OFFSET(idxd_dev, n, ofs) ((idxd_dev)->grpcfg_offset +\
(n) * GRPCFG_SIZE + sizeof(u64) * (ofs))
diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index c01db23e3333..3f922518e3a5 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -183,13 +183,6 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
portal = idxd_wq_portal_addr(wq);
/*
- * The wmb() flushes writes to coherent DMA data before
- * possibly triggering a DMA read. The wmb() is necessary
- * even on UP because the recipient is a device.
- */
- wmb();
-
- /*
* Pending the descriptor to the lockless list for the irq_entry
* that we designated the descriptor to.
*/
@@ -199,6 +192,13 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
llist_add(&desc->llnode, &ie->pending_llist);
}
+ /*
+ * The wmb() flushes writes to coherent DMA data before
+ * possibly triggering a DMA read. The wmb() is necessary
+ * even on UP because the recipient is a device.
+ */
+ wmb();
+
if (wq_dedicated(wq)) {
iosubmit_cmds512(portal, desc->hw, 1);
} else {